VAGAL NEUROMODULATION FOR DRUG-RESISTANT TRIGEMINAL NEURALGIA: A CASE SERIES

C. Tuccillo¹, A.M. Salzano², M.T. Di Dato², A. Diana¹, C. Morrone¹, M.B. Passavanti³, C. Pace³, E. Saracco², M.V. Adriani², P. Mango², D. Tammaro², A. Papa² | ¹Residency Program in Anesthesiology, Resuscitation, Intensive and Pain Therapy University of Campania "Luigi Vanvitelli", Napoli, Italy; ²Pain Department, A.O. Dei Colli - V. Monaldi Hospital, Napoli, Italy; ³Department of Women, Child and General and Specialized Surgery, University of Campania "Luigi Vanvitelli", Napoli, Italy

Introduction. Trigeminal neuralgia (TN) is a chronic neuropathic pain disorder characterized by recurrent, evocable, unilateral brief, electric shocklike pains with an abrupt onset and cessation, substantially impacting quality of life. Although pharmacotherapy is the first-line treatment, a subset of patients remains refractory [1]. Non-invasive vagal nerve stimulation (VNS) has emerged as a promising strategy for chronic pain and headache disorders [2,3]. This study aims to evaluate the clinical outcomes of retroauricular VNS in patients with drug-resistant TN.
Methods. Four patients with chronic TN were enrolled in a case series (two men, two women; aged 40–70 years) with a history of TN lasting over two years and severe pain (Numerical Rating Scale [NRS] = 10/10) despite ongoing treatment with NSAIDs, triptans, and opioids. Patients underwent non-invasive VNS for six consecutive weeks: the device was placed in the retroauricular region weekly, alternating sides. Clinical assessments were performed weekly to evaluate pain intensity (NRS), treatment response, tolerability, and adverse events. The primary outcome was pain reduction after six weeks.
Results. All patients completed the six-week protocol. At baseline, pain intensity was 10/10 on the NRS. Following retroauricular VNS, all patients experienced a progressive reduction in pain. Mean NRS scores decreased steadily until week six, when one patient achieved a score of 0 and the others a score of 2 (Table 1). The most marked improvement occurred during the first three weeks, followed by stabilization. No patient experienced worsening of symptoms or discontinued treatment, suggesting a cumulative therapeutic effect. The intervention was well tolerated; mild, transient dizziness reported during the first week resolved spontaneously. No serious adverse events occurred.
Conclusions. Retroauricular VNS was associated with substantial and progressive pain reduction in patients with long-standing, drug-resistant TN. All patients achieved significant pain relief with only mild, transient side effects. These findings suggest that retroauricular VNS may represent a safe, effective, non-invasive therapeutic option for refractory TN, supporting further investigation in larger controlled studies.